Several major technological advances have resulted in significant changes in equipment and operating procedures of commercial photofinishing systems. In the past, a customer's exposed film would be dropped off or mailed to a photofinishing center, where the film was developed, and photographic prints were then produced by printing the image frames on the developed photographic negative onto photographic paper in a multi-step optical projection sequence. As technology advanced, analog images could be transformed into digital image information by various optical scanning means. The ability to render photographic images in digital form accelerated the evolution of processes and materials which became advantageous for recording the digital information of the images on the film on a variety of media and by an assortment of techniques. For example, digital image information can now be recorded on optical disks or photo compact discs, as well as on photographic paper by devices such as digitally addressable high-speed laser printers.
It is these rapidly advancing technologies which have had a significant impact on commercial photofinishing operations. Today, a photofinisher will develop films from many customers and splice these films together so as to form a single large reel of spliced film to be deployed as a film supply reel in a high-speed film scanner. All individual sections of film on such a reel are of one and the same nominal width, for example, 35 mm film, but are typically of different section length, for example, 12 exposures, 24 exposures, or 36 exposures. Individual film sections may have a particular film speed rating (for example, ASA 100 to ASA 1000) and frequently include films by different manufacturers. Film manufacturers have established on a worldwide basis standards and specifications for splicing of films and splicing tolerances, i.e., the degree of allowable lateral offset at the splice of spliced sections perpendicular to the length of the spliced film, as well as allowable angular deviations among two adjacent spliced film sections.
When the very first splice joins two film sections such that the last frame of the first section joins the first frame of the second section, all subsequent film sections are spliced in the same manner, thereby providing a film supply reel with a "first frame first" (F.F.F.) configuration. When the first splice joins the first frame of the first film to the last frame of the second film, the completed film supply reel is said to be in a "last frame first" (L.F.F.) configuration. With respect to the emulsion face of film image frames, all optical film codes along one edge of each film section will be presented at one side for F.F.F. and the opposite side of the film for L.F.F. along the film path in a film scanner.
Suitable optical codes reflective of these film parameters are encoded during the film manufacturing process alongside each image frame of a film in proximity to one edge of the film. Thus, each image frame of a section of spliced film on a film supply reel can, in principle, be uniquely identified by its optical code as to film manufacturer, film speed rating, and number of frames on that film section. In the present invention this identification of image frames is performed by a film code reader assembly which is deposed in a film scanner at a location between the film supply reel and the film scanning module.